The use of a floppy disk as rotating magnetic recording media is well known. More specifically, a single disk is permanently encased in a protective jacket. The disk rotates within the jacket, as the jacket is held stationary within a disk drive.
The present invention is an improvement upon copending and commonly assigned U.S. Patent application Ser. No. 391,060, filed June 22, 1982 now U.S. Pat. No. 4,482,929, incorporated herein by reference. More specifically, the present invention provides reversible or two-sided use of this copending application's cartridge.
Reversibility of a floppy disk cartridge, to thereby enable read/write of a selected side of the disk, has been addressed in the prior art.
U.S. Pat. No. 3,932,895 shows a square, flexible-jacket diskette having optical-detector holes which are offset symmetrically to opposite sides of a jacket axis along which the jacket's head access openings are placed. Thus, when the jacket is flipped 180.degree. about this axis, the other side's head access opening and the other side's detector hole is properly positioned in the disk drive. In this arrangement, the head access openings run perpendicular to an edge of the cartridge. In one embodimment, the jacket's leading edge (the edge which first enters the disk drive) includes two write-enable cutouts. In this way, one of the cutouts is always in the correct position, for either flipped positions of the diskette.
The prior art also teaches single-sided diskettes having a head access opening located along a diagonal axis (i.e. an axis connecting the diskette corners) of a square diskette. U.S. Pat. Nos. 3,416,150 and 3,845,502 are exemplary. Both of these patents teach positioning or locating openings formed in the diskette. In patent '502 the locating openings are formed at the two trailing corners of the diskette; whereas, in patent '150 the locating openings are formed along the diagonal axis which includes the head access opening. In both patents, the diskette includes a rigid jacket.
Aforesaid copending and commonly-assigned U.S. Patent Application Ser. No. 391,060 discloses a square, single-sided, rigid-jacket diskette having a head access opening located along a diagonal axis. The jacket's leading edge includes locating openings or notches at the two leading corners of the diskette. A movable, rigid cleaning pad is provided on one side of the jacket. This pad lies along the aforesaid diagonal axis, but it is located adjacent the corner of the jacket opposite the head access opening. One leading corner includes a polarizing taper which insures that the diskette can be inserted into the drive in only one position; for example, the taper must be located at the left corner of the diskette's leading edge, as the diskette is held in a horizontal plane.